Increasing volumes of confidential information are routinely transmitted over public airwaves and telephone lines on a daily basis. In the banking and credit industries, for example, remote access to account information and the ability to transfer substantial sums of money through electronic funds transfers ("EFT") from a telephone, modem, or automatic teller machine ("ATM") are commonplace. Moreover, consumers are becoming more and more accustomed to shopping for goods and services and charging their purchases to credit card accounts in a single telephone transaction.
With the increased popularity of telephone lines and airwaves as the preferred media for the exchange of confidential financial and related information, the need to secure that data from unauthorized access is readily apparent. Indeed, the same factors which facilitate convenient remote access to savings, checking and credit card accounts also permit the unauthorized user of the associated confidential account data to fraudulently access such accounts, resulting in substantial abuse.
Efforts to curb the unauthorized access to and use of confidentially transmitted data have been only moderately successful. For example, the use of a personal identification number ("PIN") to access accounts is ineffective against fraudulent access once the PIN is intercepted. Moreover, the effectiveness of fixed encryption chemes is inherently limited to the extent the encryption scheme may be derived by analyzing intercepted encrypted data.
A method for encoding and decoding confidential data for transmission over public media is therefore needed which is both robust and which is not readily derivable through unauthorized access.